Roll up truck door lock and latch

ABSTRACT

A self-adjustable latch and lock device for slidable closures, most particularly for the overhead rear door on a truck, adapted for single hand operation in opening and closing the same. Associated with a pivotal hand lever is a hook arm biased by a resilient compression spring to engagement with a keeper post recessed in the sill of a truck floor. A thumb release catch is mounted on the hand lever to retain said lever in a semilock position unless the catch is manually depressed. Additionally, a safety cam latch cooperates with the outer end of the hand lever in a full-lock position to ensure latched engagement and further, may be padlocked to the hand lever for security purposes.

Unite States Patet 72] lnventors Ernest Rosehitz Kansas City; Grady L. Clyrna, Kansas City; Ernest M. Lee, Shawnee Mission, all of Kans. [21] Appl. No. 33,317 [22] Filed Apr. 30, 1970 [45] Patented Nov. 23, 1971 [73] Assignee Roll-O-Matic Chain Company Kansas City, Mo.

[54] ROLL UP TRUCK DOOR LOCK AND LATCH 7 Claims, 13 Drawing Figs. [52] [1.8. CI 292/240, 292/226 [51] Int. Cl E05c 13/02, E05c 3/ 10 [50] Field of Search 292/210, 240, 242, 226, D10. 32, 218 [56] References Cited UNITED STATES PATENTS 2,424,962 8/1947 Best 292/210 Primary E.raminer- Richard E. Moore Attorney-Scofield, Kokjer, Scofield & Lowe ABSTRACT: A self-adjustable latch and lock device for slidable closures, most particularly for the overhead rear door on a truck, adapted for single hand operation in opening and closing the same. Associated with a pivotal hand lever is a hook arm biased by a resilient compression spring to engagement with a keeper post recessed in the sill ofa truck floor. A thumb release catch is mounted on the hand lever to retain said lever in a semilock position unless the catch is manually depressed. Additionally, a safety cam latch cooperates with the outer end of the hand lever in a full-lock position to ensure latched engagement and further, may be padlockcd to the hand lever for security purposes.

PATENTEBuuv 23 ISYI 11622.1 89

sum 1 or 2 (U a 6 M 0 0 H R Ju v DMC/MM m lv 1 4., .1 r w, l f 0 h (v My 6 d O m w 4 f a m Jr, W 6 M y 7 d! v 0% w ROLL UP TRUCK DOOR LOCK AND LATCH BACKGROUND AND SUMMARY OF THE INVENTION This invention and construction is an improvement in the lock and latch devices for upwardly acting, overhead doors used as the rear closure on a freight truck. Such devices characteristically include a hand lever pivotally mounted on the door and an associated hook arm operable to engage a keeper bar recessed in the truck floor. A padlock assembly, a feature found in most devices. is associated with the hand lever and may be employed as a security measure when the hand lever is fully locked into position. An exemplification of a lock and latch of this nature appears in U.S. Pat. No. 2,966,706 to K. M. Christensen, issued Jan. 3, l96l, entitled Lock and Slidable Mounted Closures."

The known prior patent art and the commercially available locks and latches of this genre are notorious for their high number of deficiencies. A rather typical lock in this field requires a two stage action to close and firmly lock the door. With the truck door pulled down, the hook member is first positioned under a keeper bar in the truck floor to establish initial engagement. Thereafter, the operator must positively actuate the hand lever to move it to a full-lock position. Many operators establish only the initial engagement and do not force the handle into the full-lock position because this takes extra effort and time. Therefore, from a practical standpoint, the device does not function in the manner for which it was designed.

The state of the art was advanced somewhat by devices employing a safety catch to retain the hand lever in a semilock position whereby to secure at least initial engagement of the hook arm with the keeper bar. One such device incorporates three desirable locks, including a safety latch at the end of the hand lever, a snap lock catch which is separately actuated, and a padlock. However, even assuming that the padlock feature is not required for security, the two remaining locks are rarely employed at the same time. The primary reason they are not both employed is that two hands are required to unlock the hand lever; namely, one hand to move and retain the safety latch away from the hand lever and the other hand to actuate the snap lock catch and turn the hand lever. Frequently, the operator of a freight truck has only one or two packages, which can be carried under one arm, to place in the truck and is unwilling to set the packages down so both hands will be free to unlock the device from the full-lock position. in short, the net result is continuous use of the device in a semilock position with no benefit from the safety latch simply because the operator can then open the door with a single hand.

Another objectionable feature found in some devices is the use of one or more coil springs to throw the hand lever over to the open position. There is considerable possibility and history of pinching and catching one's hands between the hand lever and the door or parts of the latch itself. A particularly, hazardous spring-loaded device not only has a powerful spring, but also includes a construction on the door past which the hand lever must move when the latch is open. Here, foreseeable injury to the hands and fingers of the operator is an ever present danger.

Even ignoring the safety considerations, the use of one or more coil springs in prior art devices represents additional points of wear, expense, and possible malfunction. Such springs are undoubtedly more expensive to form and apply because they not only must be coiled, but hooks, loops, or extensions must be formed in the ends thereof for mounting between the hand lever and door. Should these springs slip from their mountings or break from wear, this otherwise questionable feature of the device is rendered inoperable.

Since it is obviously undesirable to have any part of the latch device dangling overhead into the rear opening of the truck when the door is raised, there have been attempts in the prior art to eliminate this occurrence. One solution is to providc u post extension from the door on which the hand lever rests in the open position. Such arrangement is satisfactory if the door is gradually raised when it is opened. However, a vast majority of the upwardly acting, rear truck doors are counterbalanced to facilitate ease of opening and the common practice among operators is to apply an initial jerk to the door which is then forcefully opened by the counterweight apparatus. lf opened in this manner, the door, upon reaching the top, experiences a recoil bounce from the counterweight that dislodges the hand lever from the post extension and will likely bang against the overhead structure of the truck as well as pivot around and hang into the rear opening.

Truck lines generally consider the service life of a truck to be from 3 to 5 years. It would be very desirable that the lock and latch of the rear door last the life of a truck. However, this may be quite an achievement as one can easily anticipate'the abuse and punishment of continuous service to which the latch device is subjected. To withstand such treatment, a durable and rugged construction is an absolute necessity to ensure extended use.

in this connection, many currently available devices have no adjustment for keeping the overhead door tight against the floor sill and, therefore, wear from continued use results in an extremely loose fit. Screw adjustments known to the art are undependable because of the tendency to loosen when subjected to the jars and jolts inherent with normal opening and closing of the door, as well as with the movement of the truck itself. Heretofore, a self-adjusting lock and latch was virtually foreign to the prior art.

Likewise, when severe wear of parts is anticipated, the problems of maintenance, repair, cleaning and replacement are substantial design considerations. The rising cost of labor and materials dictates that a truly useful latch device is one which requires minimal maintenance and repair. On the other hand, if repair is necessary, an ideal device would be one easily disassembled nd reassembled with few working parts.

There is a pressing need in the industry for a lock and latch which cures the infirmities found in commercially available devices and the prior patent art. Likewise, there is a need for a lock and latch which is designed with an acute awareness of the problems and common practices of truck operators. The primary object of this invention is to meet these needs.

More specifically, an object of this invention is to provide an improved lock and latch to bias a slidable closure against an abutment sill and in which the entire opening or closing process thereof can be accomplished by a single hand of the operator.

Another object of the invention is to provide a lock and latch in which the hook arm need not be separately positioned under a keeper bar but rather the hook arm is controlled by the hand itself and urged to engagement with the keeper bar by movement of the hand lever alone.

Another object of the invention is to provide a lock and latch having a thumb-actuated safety catch associated with the hand lever thereof. This catch is analogous to the push-in thumb latch on automobiles and is far more natural for operation since the hand of the operator need not be moved from the hand lever in order to actuate the safety catch.

An additional object of the invention is to provide a lock and latch of the character described which can be actuated in complete safety to the operator. Powerful springs to throw the lever arm from the full-lock to open position are eliminated and the entire arcuate movement of the lever is controlled by the operator. Likewise there are no obstructions past which the hand of the operator must move in either opening or closing the lock and latch and thus, the possibility of injury is greatly reduced.

Another object of the invention is to provide a lock and latch which incorporates four desirable locking features for single hand operation. These features include a hand lever controlled hook arm, a thumb-actuated safety catch, a safety cam latch, and a padlock assembly.

Yet another object of the invention is to provide a lock and latch of the character described in which, from the full-lock position, the operator merely rotates the safety cam latch to trigger a popup feature of the hand lever which moves the same a very minute distance to retain the cam latch in the rotated position. Thereafter, the operator simply transfers his hand to the hand lever and completes the opening process.

A further object of the invention is to provide a. lock and latch for an overhead, rear truck door in which the hand lever is retained in an open position above the abutting surface of the door even if the door is subjected to a jar or jolt. Therefore, no parts of the latch dangle overhead into the rear opening when the door is raised.

Another object of the invention is to provide a lock and latch which tightly keeps the closure biased to the sill. A selfadjusting feature automatically compensates for continuous wear of the various members to ensure a tight-biasing relationship throughout the service life of the latch.

Yet a further object of the invention is to provide a lock and latch of the character described which is extremely rugged and durable in construction and operation. Yet, the mechanism can be easily and quickly disassembled should maintenance be necessary.

Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.

DESCRIPTION OF THE DRAWINGS In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith, and in which like reference numerals are used to indicate like parts in the various views:

FIG. I is an exterior side view of a lock and latch constructed in accordance with a preferred embodiment of the invention and shown mounted on a fragmentary portion of an overhead, rear truck door;

FIG. 2 is an interior side view of the lock and latch shown in FIG. I, that is, a side view taken from the inside of the truck;

FIG. 3 is an enlarged plan view of the lock and latch of FIGS. 1 and 2 with parts thereof cut away and shown in section to better illustrate the construction;

FIG. 4 is an inverted side view of the lock and latch along line 4-4 of FIG. 3 in the direction of the arrows;

FIG. 5 is a bottom view along line 5-5 of FIG. 4 in the direction of the arrows;

FIG. 6 is an enlarged end view along line 6-6 of FIG. 1 in the direction of the arrows;

FIG.'7 is an exterior side view like that of FIG. 1, but showing the lock and latch engaged with a keeper recessed in the truck floor to bias the door to the floor sill;

FIG. 8 is a side view showing a first stage in the opening of the lock and latch with the safety cam latch being rotated to release the hand lever, whereupon the thumb catch is depressed to permit the hand lever to be moved to the next position;

FIG. 9 is a fragmentary side view showing a second stage in the opening of the lock and latch wherein the hand lever is rotated counterclockwise to a substantially vertical position, and further showing portions of the housing cut away to better illustrate the construction;

FIG. 10 is a view showing a third stage in the opening process with the hand lever rotated to the open position, approximately l80 from the position as shown in FIG. 7;

FIG. 11 is a view showing a first stage in the locking process wherein the hook arm is forced in a clockwise direction to engage the keeper, and further showing portions of the housing cut away to better illustrate the construction;

FIG. 12 is a view showing a second stage in the locking and latching process wherein the hand lever is rotated in a clockwise direction to engage the safety cam latch and the hook arm is more positively engaged with the keeper; and

FIG. 13 is an enlarged sectional view along line 13-13 of FIG. 3 in the direction of the arrows.

As previously mentioned, this invention relates to a lock and latch for slidable closures, particularly upwardly acting doors such as used for the rear closure on a freight truck, to bias the same against a floor sill or other abutment. Referring first to FIGS. 7 through 12, these views of the rear floor level of a truck illustrate a floor sill 20, in section, having an upper surface 20a abutted by the lower edge 21a of an upwardly acting, overhead door 21. Centrally provided in the truck floor is a rectangular recess or slot, generally designated by the numeral 22, which includes a front wall 23, sidewalls 24 and 25, and a rear wall (not shown). It may be assumed in FIGS. 7 through 12 that the truck floor extends outwardly toward the viewer from the sectioned sill 20 to provide a conventional loading shelf on the truck rear.

On the exterior surface of the door 21 is mounted a hanger 26 to which a strap 27 is attached. Likewise, a conventional handle 28 is also mounted on the exterior of the door 21. The strap 27 is employed by the operator to pull down the door 21 from an elevated position, while handle 28 is used in raising the door or at least in starting the door upwardly, as the majority of overhead truck doors are counterbalanced.

The structural details of the lock and latch, now to be described, are best understood with reference to FIGS. 1-6 and 13. Referring then to FIG. 3, a pair of openings or recesses 29 and 30 are provided through the truck door 21 near the lower edge thereof. A metal plate 31, preferably steel, is removably but rigidly attached to the door 21 by a plurality of bolts 32. A pair of openings 33 and 34 are provided in the plate 31 to match respectively with the recesses 30 and 29 in the door 21. A metal liner 35 is attached to the rear surface of the plate 21 and projects inwardly into the recess 29.

The body, or hand lever, of the truck lock and latch has an outer facing plate preferably of integral sheet steel construction and generally designated by the numeral 36, which includes a hub portion 360, a safety catch portion 36b, a hand grip portion 36c, and a right angle abutment flange 36d at the outer end of the grip portion 360.

Particularly referring to FIG. 4, a continuous housing shield, generally designated by the numeral 37, is integrally attached along the edge of the rear face of the outer plate 36 and projects toward the door 21 to act as a hood over the hub portion 36a and the safety catch portion 36b. More particularly, the shield 37 includes a straight portion 37b aligned with the upper edge of the safety catch portion 36b (near the bottom of the view in FIG. 4). Portion 37c bounds the safety catch portion 36!: from the grip portion 3360 Likewise, the portion 37d is aligned with the bottom edge of the safety catch portion 36b to provide a semirectangular closure 3% on the rear face thereof. The forward end of the portion 37d abuts a solid metallic block 38 having a cylindrical bore 39 therein which opens to the semirectangular closure. The block 38 is rigidly affixed or welded to the rear face of the safety latch portion 37b.

From the straight portion 37b of the shield 37, an arcuate portion 37a extends around the upper edge of the hub portion 36a and terminates to provide a stop 37] located somewhat past I from the straight portion 37b.

A central bore 40 through the hub portion 360 receives the shaft of a pivot pin or bolt 41 having a flat head 41a of greater diameter than the bore 40. Likewise, the pin 41 extends through the openings 33 in the plate 3] and into the recess 30 of the door 21. Pivotally carried on the shaft of the pin 41 is a cylindrical sleeve 42 of a hook ann which has an extension 42a terminating in hook 42b. Nut 43, disposed within the recess 30, secures the pin 41 between the plate 31 and sleeve 42, while washer 44a is interposed between the rear face of the hub portion 360 and sleeve 42. Additionally, one or more washers 44 of suitable diameter and thickness space the hand lever outwardly with respect to plate 31 to provide clearance of the heads of the bolts 32.

Attention is now directed to the safety catch portion 36b wherein is found a thumb-actuated safety catch. An opening 45 through the shield portion 37b is aligned with an internally threaded recess 46 in the upper portion of the block 38. A bolt 47 extends through the opening 45 and is threadably received within the recess 46. Pivotally carried on the bolt 47 is a catch lever having a body portion 48a terminating in an outwardly projecting portion 48b at one end thereof and terminating in an inwardly projecting knob 48c at the opposite end thereof. The outwardly projecting portion 48b extends through an opening 52 in the catch portion 36b and has a thumb plate 50 attached thereto which is larger than the opening 52. The knob 480 is less in size than the opening 34 in plate 31 and includes a cylindrical recess 51 therein to receive a spring 53 which operates against the rear face of the catch portion 36b to urge the knob 480 into the opening 34.

As previously mentioned, the block 38 has a cylindrical bore 39 therein. The bore 39 is necked down within the block 38 to provide a shoulder 39a to a smaller bore 3% extending through the remaining portion of the block 38 and opening to the semirectangular closure 372. The smaller bore 39b receives an elongate plunger shaft 54 having a removable locking pin 55 in one end thereof and an enlarged head 56 at the opposite end thereof. A spring 57 communicates between the enlarged head 56 and the shoulder 39a to urge the head 56 away from the block 38, but such action is limited by the locking pin 55 engaging the block 38.

The plate 31 includes an additional opening or port 58, similar to the opening 34, which is radially disposed from the pivot pin 41 the same distance as is the opening 34 to permit the knob 48c to register with and be received within the port 58 when the hand lever is rotated to the position as shown in FIG. 10. As viewed in FIG. 13, the lower edge 58b of the port 58 is sharp or square and the upper edge 58a thereof is beveled. The purpose of this distinction will later be described.

Also mounted on the door 21, near the outer end of the hand lever, is a plate 60 secured thereto by bolts 61. A post 62 projects outwardly from the plate 61 to pivotally support a cam latch 63. The cam latch 63 is irregular in form and so shaped at 63a as to flatly abut the flange 36d. An indentation or finger groove 63b is adapted to pivot the latch 63 around post 62 as will later be described. The lower portion 630 of the latch 63 which provides the flat surface 630 has a hole 65 therethrough to match the opening 59in the flange 36d for the insertion of the loop 67a of a conventional padlock 67 as shown in FIG. 1.

The latch 63 further includes a camming surface 63d on a circular arc with respect to the pivot axis of post 62 beginning at the upper end of the flat surface 63a and terminating somewhat less than 90 therefrom. In addition, a stop surface 63e (FIG. 5) on the rear side of the latch 63 engages the head of the lower bolt 61 to limit clockwise rotation of the latch 63 relative to the views in FIGS. 1, 7,8 or 12.

Referring particularly to FIG. I and FIGS. 7 through I2, and starting from the full-lock position with the padlock 67 in place, the following description illustrates the opening and closing sequence.

1. The padlock 67 is opened and the loop 670 is removed from the holes 59 and 65 in the flange 36d and cam latch portion 630, respectively.

2. Since the hand lever cannot 63 in position, the latch 63 is direction relative to FIG. 7 by means of finger engagement with the groove 63b. During this action, the camming surface 63d engages the upper edge of the flange 36d until the latch 63 is rotated somewhat less than 90 as viewed in FIG. 8. When the upper edge of the flange 36d no longer engages the camming surface 63d, the spring 57 acts against plunger head 56 which is urged against the extension 420 of the hook arm to slightly pop up the hand lever around the pivot pin 41 to the position as shown in FIG. 8. Further such movement of the hand lever is limited by the knob 48c projecting into the opening 34 in plate 31.

3. At this point, the operator transfers his hand from the cam latch 63 to the grip portion 36c ofthe hand lever since the latch 63 is now held open by the flange portion 36d. Thereafter, by using his thumb, the operator depresses the be moved with the cam latch pivoted in a counterclockwise thumb plate 50 which removes the knob 480 from the opening 34. With the thumb catch depressed against its spring load, the operator then lifts the hand lever in a counterclockwise direction around the pivot pin 41 until the knob 480 is moved past the opening 34 in plate 31. At this point, if he so desires, the operator may shift his grip on the hand lever. Once the hand lever clears the latch 63, it rotates clockwise under its own weight until the stop surface 63c hits the head of lower bolt 61 to the position to FIG. 7.

4. When the hand lever is rotated around pivot pin 41 in a counterclockwise direction approximately to the position as shown in FIG. 9, the extension 42a of the hook arm is engaged by the stop 37f of the housing shield 37 and further counterclockwise rotation of the hand lever causes the hook 42b to disengage the keeper bar 66 which is disposed within the recess 22 in the floor of the truck.

5. When the hand lever is rotated approximately 180 to the position as shown in FIG. 10, the knob 48c registers with the port 58 and is urged into the same by the spring 53. The sharp edge 58d of the port 58 prevents further counterclockwise rotation of the hand lever unless the thumb catch is depressed. At this point, the operator can raise the door 21 by means of the handle 28 or otherwise. The hand lever is retained in the open position by the knob 48c extending into the port 58, even if the door 21 is vigorously raised and experiences a recoil bounce from the counterweight apparatus. The beveled edge 58a provides a sufiicient retaining force to the knob 480 if such occurs.

6. The door 21 thereafter may be lowered with the aid of the strap 27 or otherwise. In order to relock the door 21, the operator merely grasps the grip portion 36c and applies a force to rotate the hand lever in a clockwise direction as viewed in FIG. 10. The thumb plate 50 need not be depressed as the knob 48c rides over the beveled edge 58a of the port 58. Although the beveled edge 58a provides enough resistance to withstand a recoil bounce when the door 21 is raised, it does not provide substantial resistance to the force the operator would normally apply in rotating the hand lever.

7. When the hand lever is rotated approximately to the position as shown in FIG. 11, the end of the hook 42b engages the keeper 66. Further clockwise rotation forces the hook 42b under the keeper 66 via the spring loaded plunger with head 56 urged against the extension 420.

8. When the hand lever is rotated to the position as shown in FIG. 12, the lower edge of the flange 36d engages the upper surface of the cam latch 63. Further clockwise rotation of the hand lever causes the cam latch 63 to yieldingly pivot in a counterclockwise direction until the hand lever is rotated to the full-lock position. At this point, the latch 63 swings back, under its own weight, to the position as shown in FIG. 7. Thereafter, the padlock 67 may be applied for security purposes.

In connection with the final step positioning the hand lever to the full-lock position, it should again be noted the very minute movement of the hand lever between the position at which the knob 48c first registers with the opening 34 as viewed in FIG. 8 and the full-lock position as viewed in FIG. 7. On closing, if extra time and effort is taken and if the hand lever is very gradually and slowly rotated downwardly, it may be possible to achieve a position similar to that as shown in FIG. 8 with the cam latch 63 held away from the hand lever. However, by normally closing the latch, the momentum of the lever and hand of the operator carries the lever past the position in FIG. 8 to the full-lock position in FIG. 7, which virtually eliminates the possibility of improper use of the device and ensures benefit of the safety feature provided by the cam latch 63.

The spring-loaded plunger with head 56 urged against the extension 42a of the hook arm accomplishes two separate functions. First, as previously mentioned, the plunger provides the pop up action of the hand lever when the cam latch 63 is rotated in the initial opening process. Secondly, the plunger cooperates with the hook arm to provide a self-adjusting feature which ensures a biasing relationship between the door 21 and the floor sill 20 even after prolonged use. The rear of the hook 62b is built up or tapered toward the extension 420. Should various parts of the lock and latch or the keeper 66 become worn from continued use, the plunger assembly causes the hook arm to engage the keeper 66 further back into the hook 42b to thereby ensure a tight fit.

Likewise, it should be noted that disassembly of this lock and latch is extremely convenient. With the nut 43 removed from the pin 41, the entire hand lever can be removed from the door, thus exposing all the members housed within the shield 37. The entire hand lever and plate 31 can be as easily removed simply by removing the bolts 32.

From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombina tions are of utility and may be employed without reference to other features and subcombinations.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense,

Having thus described our invention. we claim:

1. In combination with an abutment sill having a keeper recessed therein and a slidable closure, a lock and latch device comprising:

a pivot pin attached to said closure and therefrom;

a hand lever pivotally carried on said rotatable therearound;

a hook also pivotally carried on said pin and associated with said hand lever for limited pivotal movement with respect thereto, but rotatable around said pin in response to rotational movement ofsaid hand lever,

said hook and lever cooperatively positionable by rotational movement around said pin to a full-lock position in which said hook engages said keeper to bias said closure to said abutment sill and to an open position in which said hook disengages said keeper to permit movement of said closure relative to said abutment sill; and

a resilient plunger mechanism connected to said hand lever to bias said hook to said keeper when said hand lever is projected outwardly pin and manually moved to said full-lock position thereby to ensure snug engagement between said closure and abutment sill regardless of wear on said keeper and hook caused by prolonged usage.

2. The combination as in claim 1, said plunger mechanism including a block attached to said hand lever and having a central bore therein, a plunger rod slidably received within said bore, and spring means cooperating between said block and plunger rod to urge said rod against said hook.

3. The combination as in claim 1 including a catch recess in said closures and depressible catch means mounted on said hand lever to cooperate with said catch recess in preventing movement of said lever from said full-lock position to said open position unless said means is depressed.

4. The combination as in claim 3, said depressible catch means comprising a lever member mounted intermediate the ends thereof to said hand lever for limited pivotal movement, one end of said lever member terminating in a catch knob and the other end terminating in a depressible projection, and spring means engaging said lever member to urge said catch knob toward said closure and into said catch recess when said hand lever is moved to said full-lock position.

5. The combination as in claim 3 including a recess port in said closure with which said catch means registers when said hand lever is moved to said open position to retain said lever in said open position.

6. The combination as in claim 1 including a post attached to said closure, remote from said pin and projected outwardly therefrom, and a safety latch rotatably mounted on said post and having a hand lever engaging cam surface to permit movement of said hand lever from said open position to said fulllock position, but to prohibit movement of said hand lever from said full-lock position to said latched position unless said safety catch is rotated from engaging relationship with said hand lever,

said plunger mechanism operable to automatically move and retain said hand lever past said cam surface when said safety catch is rotated from engaging relationship with said hand lever, without influencing the engaging relationship between said keeper and hook. 7. The combination as in claim 6, said hand lever including a padlock bore therein and said safety catch including a padlock bore therein aligned with the bore of said hand lever and also including a finger indentation to facilitate rotational movement ofsaid catch about said post. 

1. In combination with an abutment sill having a keeper recessed therein and a slidable closure, a lock and latch device comprising: a pivot pin attached to said closure and projected outwardly therefrom; a hand lever pivotally carried on said pin and manually rotatable therearound; a hook also pivotally carried on said pin and associated with said hand lever for limited pivotal movement with respect thereto, but rotatable around said pin in response to rotational movement of said hand lever, said hook and lever cooperatively positionable by rotational movement around said pin to a full-lock position in which said hook engages said keeper to bias said closure to said abutment sill and to an open position in which said hook disengages said keeper to permit movement of said closure relative to said abutment sill; and a resilient plunger mechanism connected to said hand lever to bias said hook to said keeper when said hand lever is moved to said full-lock position thereby to ensure snug engagement between said closure and abutment sill regardless of wear on said keeper and hook caused by prolonged usage.
 2. The combination as in claim 1, said plunger mechanism including a block attached to said hand lever and having a central bore therein, a plunger rod slidably received within said bore, and spring means cooperating between said block and plunger rod to urge said rod against said hook.
 3. The combination as in claim 1 including a catch recess in said closure and depressible catch means mounted on said hand lever to cooperate with said catch recess in preventing movement of said lever from said full-lock position to said open position unless said means is depressed.
 4. The combination as in claim 3, said depressible catch means comprising a lever member mounted intermediate the ends thereof to said hand lever for limited pivotal movement, one end of said lever member terminating in a catch knob and the other end terminating in a depressible projection, and spring means engaging said lever member to urge said catch knob toward said closure and into said catch recess when said hand lever is moved to said full-lock position.
 5. The combination as in claim 3 including a recess port in said closure with which said catch means registers when said hand lever is moved to said open position to retain said lever in said open position.
 6. The combination as in claim 1 including a post attached to said closure, remote from said pin, and projected outwardly therefrom, and a safety latch rotatably mounted on said post and having a hand lever engaging cam surface to permit movement of said hand lever from said open position to said full-lock position, but to prohibit movement of said hand lever from said full-lock position to said latched position unless said safety catch is rotated from engaging relationship with said hand lever, said plunger mechanism operable to automatically move and retain said hand lever past said cam surface when said safety catch is rotated from engaging relationship with said hand lever, without influencing the engaging relationship between said keeper and hook.
 7. The combination as in claim 6, said hand lever including a padlock bore therein and said safety catch including a padlock bore therein aligned with the bore of saiD hand lever and also including a finger indentation to facilitate rotational movement of said catch about said post. 